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Related papers: Spiral-wave-driven accretion in quiescent dwarf no…

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Motivated by the recent results of \citet{Lesur_Ogilvie10} on the transport properties of incompressible convection in protoplanetary discs, in this paper we study the role of compressibility and hence of another basic mode -- spiral…

Solar and Stellar Astrophysics · Physics 2015-05-28 G. R. Mamatsashvili , W. K. M. Rice

We numerically study the tidal instability of accretion discs in close binary systems using a two-dimensional SPH code. We find that the precession rate of tidally unstable, eccentric discs does not only depend upon the binary mass ratio q.…

Astrophysics · Physics 2009-10-30 James Murray

We show that dwarf nova disks in quiescence have rather low magnetic Reynolds number, of order 10^3. Numerical simulations of magnetized accretion disks suggest that under these conditions magnetohydrodynamic turbulence and the associated…

Astrophysics · Physics 2009-10-30 Charles F. Gammie , Kristen Menou

The status of our current understanding of angular momentum transport in accretion disks is reviewed. The last decade has seen a dramatic increase both in the recognition of key physical processes and in our ability to carry through direct…

Astrophysics · Physics 2008-11-26 Steven A. Balbus

The recurrent outbursts that characterise low-mass binary systems reflect thermal state changes in their associated accretion discs. The observed outbursts are connected to the strong variation in disc opacity as hydrogen ionises near 5000…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Henrik N. Latter , John C. B. Papaloizou

Two-dimensional numerical simulations of an accretion flow in a close binary system are performed by solving the Euler equations with radiative transfer. In the present study, the specific heat ratio is assumed to be constant while…

Astrophysics · Physics 2009-11-07 Jun'ichi Sato , Keisuke Sawada , Naofumi Ohnishi

In a standard, steady, thin accretion disc, the radial distribution of the dissipation of the accretion energy is determined simply by energy considerations. Here we draw attention to the fact that while the (quasi-)steady discs in dwarf…

High Energy Astrophysical Phenomena · Physics 2019-09-04 C. J. Nixon , J. E. Pringle

We argue that the quiescent value of the viscosity parameter of the accretion disc in WZ Sge may be alpha_{cold}~0.01, in agreement with estimates of alpha_{cold} for other dwarf novae. Assuming the white dwarf in WZ Sge to be magnetic, we…

Astrophysics · Physics 2008-11-26 O. M. Matthews , R. Speith , G. A. Wynn , R. G. West

At the final stages of a supermassive black hole coalescence, the emission of gravitational waves will efficiently remove energy and angular momentum from the binary orbit, allowing the separation between the compact objects to shrink. In…

High Energy Astrophysical Phenomena · Physics 2020-10-14 Camilo Fontecilla , Giuseppe Lodato , Jorge Cuadra

We perform 2D and 3D numerical simulations of an accretion disc in a close binary system using the Simplified Flux vector Splitting (SFS) finite volume method. In our calculations, gas is assumed to be the ideal one, and we calculate the…

Astrophysics · Physics 2009-10-30 Makoto Makita , Kenji Miyawaki , Takuya Matsuda

We use the Shaviv and Wehrse (1991) code to model the vertical structure and the emission properties of quiescent dwarf nova discs. We find that in the case of HT Cas the quiescent disc must be optically thin, in contradiction with the…

Astrophysics · Physics 2009-10-30 Irit Idan , Jean-Pierre Lasota , Jean-Marie Hameury , Giora Shaviv

In this paper, we extend our previous analysis (Lodato & Rice 2004) of the transport properties induced by gravitational instabilities in cooling, gaseous accretion discs to the case where the disc mass is comparable to the central object.…

Astrophysics · Physics 2009-11-10 G. Lodato , W. K. M. Rice

Circumplanetary disks (CPDs) control the growth of planets, supply material for satellites to form, and provide observational signatures of young forming planets. We have carried out two dimensional hydrodynamical simulations with radiative…

Earth and Planetary Astrophysics · Physics 2016-12-20 Zhaohuan Zhu , Wenhua Ju , James M. Stone

The phenomenological Disc Instability Model has been successful in reproducing the observed light curves of dwarf nova outbursts by invoking an enhanced Shakura-Sunyaev $\alpha$ parameter $\sim0.1-0.2$ in outburst compared to a low value…

High Energy Astrophysical Phenomena · Physics 2016-08-17 M. S. B. Coleman , I. Kotko , O. Blaes , J. -P. Lasota , S. Hirose

In this note we study the accretion disc that arises in hypercritical accretion of $\dot M\sim 10^8 M_{\rm Edd}$ onto a neutron star while it is in common envelope evolution with a massive companion. In order to raise the temperature high…

Astrophysics · Physics 2009-10-31 G. E. Brown , C. -H. Lee , H. A. Bethe

Hydrodynamic simulations have been used to study accretion disks consisting of counterrotating components with an intervening shear layer(s). Configurations of this type can arise from the accretion of newly supplied counterrotating matter…

Astrophysics · Physics 2009-10-31 O. A. Kuznetsov , R. V. E. Lovelace , M. M. Romanova , V. M. Chechetkin

The eruptive cycles of dwarf novae (DN) are thought to be due to a thermal-viscous instability in the accretion disk surrounding the white dwarf (WD). This model has long been known to imply a stress to pressure ratio \alpha ~0.1 in…

Solar and Stellar Astrophysics · Physics 2018-01-17 N. Scepi , G. Lesur , G. Dubus , M. Flock

Accretion discs properties should deviate from standard theory when magnetic pressure exceeds the thermal pressure. To quantify these deviations, we present a systematic study of the dynamical properties of magnetically arrested discs…

High Energy Astrophysical Phenomena · Physics 2023-10-26 Nicolas Scepi , Mitchell C. Begelman , Jason Dexter

Dwarf novae (DNe) are accreting white dwarfs that show eruptions due to a thermal-viscous instability in the accretion disk. The outburst timescales constrain $\alpha$, the ratio of the viscous stress to the thermal pressure, and so the…

High Energy Astrophysical Phenomena · Physics 2018-12-05 Nicolas Scepi , Geoffroy Lesur , Guillaume Dubus , Mario Flock

We present three dimensional smoothed particle hydrodynamics (SPH) calculations of warped accretion discs in X-ray binary systems. Geometrically thin, optically thick accretion discs are illuminated by a central radiation source. This…

Astrophysics · Physics 2009-11-11 Stephen B. Foulkes , Carole A. Haswell , James R. Murray